Nuclear envelope organization in papillary thyroid carcinoma

• Fischer, A.H. ^[1] ; Taysavang, P. ^[1] ; Weber, C.J. ^[1] ; Wilson, K.L. ^[2]
  1. [1] Emory University

     Emory University

     Estados Unidos

     
  2. [2] Johns Hopkins University

     Johns Hopkins University

     Estados Unidos

     
• Localización: Histology and histopathology: cellular and molecular biology, ISSN-e 1699-5848, ISSN 0213-3911, Vol. 16, Nº. 1, 2001, págs. 1-14
• Idioma: inglés
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• Resumen

  • Papillary thyroid carcinomas (PTCs) have characteristic nuclear shape changes compared to fo lli cular-type thyroid epithelium. We tested the hypothesis that the altered nuclear shape results from altered distribution or expression of the major structural proteins of the nuclear envelope. Lamin A, lamin Bl, lamin C, lamin B receptor (LBR), lami na-associated polypeptide 2 (LAP2), emerin, and nuclear pores were examined. PTC's with typical nuclear features by H&E were compared to non-neoplastic thyroid and follicular neoplasms using confocal microscopy, and semiquantitative immunoblotting. Lamin A/C, lamin Bl, LAP2, emerin, and nuclear pores all extend throughout the grooves and intranuclear inclusions of PTe. Their distribution and fl uorescent intensity is not predictably altered relative to nuclear envelope irregularities. By immunoblotting, the abundance (per ce ll) and electrophoretic mobilities of lamin A, lamin Bl, lamin C, emerin, and LAP2 proteins do not distinguish PTC, normal thyroid, or follicular neoplasms. These results do not support previously published predictions that lamin A /C exp ression is related to a loss of proliferative activity. At least three LAP2 isoforms are identified in normal and neoplastic thyroid. LBR is sparse or undetectable in all the thyroid samples. The results suggest that the irregular nuclear shape of PTC is not determined by these nuclear envelope structural proteins per se. We review the structure of the nuclear envelope, the major factors that determine nuclear shape, and the possible functional consequences of its alteration in PTe.